The present invention relates generally to a vibratory plow which is adapted to lay cable, flexible pipe, and the like underground in the cut made by a blade wherein the blade is vibrated to reduce the force required to pull the blade through the ground. More particularly, the present invention relates to a vibratory plow assembly having a multiple-edge sod cutter which slices the thatch or ground covering and breaks the sod ahead of the plow blade.
Vibratory cable plows have been used for several years to lay cable, flexible pipe, and the like underground. The cable or pipe may be either pulled through the cut of the plow blade, or a cable chute may be provided on the trailing edge of the plow blade which guides the cable or pipe into the ground from a drum mounted on the tractor or other vehicle. Various types of vibrators have been mounted on the plow blade, or the vibrator and blade have been suspended together on a resilient frame assembly to generate either vertical or orbital motion in the plow blade. Examples of such prior art vibratory plows are disclosed in U.S. Pat. Nos. 4,040,261, 3,618,237 and 3,363,423, all assigned to the assignee of the present invention.
A preferred frame assembly of prior art vibratory plows, as shown in the above-referenced patents, includes two pairs of parallel side links which are resiliently supported by pivotal connections to forward and rearward frame members comprising generally vertical stanchions or columns. The plow blade and vibrator are supported by the rearward frame member. The vibrator generates substantially vertical vibrations in the plow blade when the vehicle is stationary and orbital vibration in the blade as the blade is pulled through the ground.
In vibratory plow constructions of the type just described, it is often advantageous to slice the thatch or ground covering and break the sod which precedes the cable-laying plow blade. This prevents grass, weeds, and other debris from wrapping about the skid shoes or plow blade, thereby making the plowing more efficient.
In known sod cutter constructions, a single cutting edge has been used to slice the thatch and break the sod ahead of the plow blade. However, since the single cutting edge wears rapidly and loses its sharpness, thereby becoming less efficient, it must be changed and replaced frequently. Thus, there has been a need for an improved sod cutter that eliminates the disadvantages and limitations of known constructions.
It is, therefore, a principal object of the present invention to provide a sod cutter construction which does not require frequent sharpening or replacement. Further, it is an object of the present invention to provide improved slicing of the thatch or ground cover and breaking of the sod that precedes the cable-laying plow blade.